The principles of the silver complex diffusion transfer reversal process, hereinafter called DTR-process, have been described e.g. in U.S. Pat. No. 2,352,014 and in the book "Photographic Silver Halide Diffusion Processes" by Andre Rott and Edith Weyde--The Focal Press--London and New York, (1972).
In the DTR-process non-developed silver halide of an information-wise exposed photographic silver halide emulsion layer material is transformed with a so-called silver halide solvent into soluble silver complex compounds which are allowed to diffuse into an image-receiving element and are reduced therein with a developing agent, generally in the presence of physical development nuclei, to form a silver image having reversed image density values ("DTR-image") with respect to the black silver image obtained in the exposed areas of the photographic material.
A DTR-image bearing material can be used as a planographic printing plate wherein the DTR-silver image areas form the water-repellant ink-receptive areas on a water-receptive ink-repellant background. A particular interesting type of photographic material for making a printing plate according to the DTR-process comprises in the order given on a support a silver halide emulsion layer and a physical development nuclei containing layer as a surface layer. Such type of photographic material is commercially available under the tradename of SUPERMASTER from Agfa-Gevaert NV and from Mitsubishi Paper Mills under the tradename SILVERMASTER.
These commercial printing plates are generally processed by means of camera plate makers that include an exposure unit as well as a developing unit. As a result of a demand on the market to reduce the time needed for producing a printing plate, the processing times in such camera plate makers have been shorted.
In particular the time that lapses between entrance of the photographic material into the developing liquid and exit of the photographic material out of the developing liquid is substantially reduced. Typically the time has been reduced to less than 15s and may even be less than 10s.
It has now been found by us that the automatic processing of a photographic material according to the DTR-process in a camera plate maker that uses short development times of 15s or less, results in printing plates of inferior quality. In particular, it was found that when the plates were stored for some time after plate-making but before actual printing, the printing endurance was much less than in case the printing plate was used to print immediately after plate-making.